System and method for controlling the stopping operations of weaving machines

Abstract

A system for controlling the stopping sequence of a plurality of weaving machines under emergency conditions and a method for the same are disclosed. The system includes a preference control circuit which upon receipt of high and low priority emergency signals from detectors activates a brake actuator to stop the associated weaving machine under the emergency condition of high priority which calls for immediate action, while introducing a delay to the corrective action to be taken in respect of the weaving machine under the emergency condition of low priority not requiring immediate action.

What is claimed is: 
     
       1. A system for controlling the sequence of stopping operations of a plurality of weaving machines during emergency conditions to minimize the loss of time due to the stoppage, comprising: first and second detectors associated with each one of said weaving machines for generating high and low priority emergency signals respectively when the associated weaving machine is under an emergency condition of high or low priority; and   preference controlling means for activating a brake actuator of the associated weaving machine in response to the presence of said high priority emergency signal and to the presence of said low priority emergency signal in the absence of high priority emergency signal generated from the detector associated with another weaving machine and activating said brake actuator after the elapse of a predetermined period of time in response to said low priority emergency signal in the presence of said another high priority emergency signal.   
     
     
       2. A system as claimed in claim 1, wherein said preference controlling means comprises a logic gate means associated with said first and second detectors for permitting the passage of the high priority emergency signal to the brake actuator of the associated weaving machine and timing means associated with the second detector for permitting the passage of the low priority emergency signal to said brake actuator after the elapse of a predetermined time period from the time of occurrence of the last-mentioned signal in the presence of another high priority emergency signal generated from the first detector associated with another weaving machine. 
     
     
       3. A system as claimed in claim 1 or 2, wherein said preference controlling means comprises: a pulse generator for generating clock pulses;   a timing means responsive to said low priority emergency signal for generating an output after the elapse of a predetermined time period;   a counter means for each one of said weaving machines for counting a train of clock pulses in response to the output of said timing means;   a maximum detecting means associated with each one of said weaving machines for detecting the maximum value of the counts respectively stored in the counter means associated with the other weaving machines;   a comparator means; and   a logic circuit means for providing one of first and second logic states depending upon the presence of another high priority emergency signal and the presence of another low priority emergency signal to cause said comparator means to compare said count stored in said counter means with a predetermined value in response to said first logic state and cause said comparator means to compare said stored count with the detected maximum value in response to said second logic state; and   a switching means responsive to an output from said comparator means to activate said associated brake actuator.   
     
     
       4. A system as claimed in claim 3, wherein said logic circuit comprises means associated with each one of said weaving machines to respond to the presence of a high priority emergency signal and to the absence of any other low priority emergency signal to generate a first signal representing said first logic state and respond to the absence of a high priority emergency signal which occurs simultaneously with the presence of any other low priority emergency signal to generate a signal representing said second logic state. 
     
     
       5. A system as claimed in claim 3, wherein said logic circuit means comprises: means for detecting the number of said low priority emergency signals generated from the second detectors associated with all of said weaving machines;   means for multiplying said detected number of the low priority emergency signals by a predetermined multiplication factor which represents the number of maintenance personnels required for attending to a single weaving machine under the low priority emergency condition;   means for providing summation of said multipled number and the number of the high priority emergency signals generated from the first detectors associated with all of said weaving machines; and   second comparator means for comparing the summation output with a reference value representing the maximum number of maintenance personnels to generate a first signal representing said first logic state when said summation output is greater than said reference value and a second signal representing said second logic state when said summation output is smaller than said reference value.   
     
     
       6. A system as claimed in claim 1 or 2, further comprising a third detector associated with each one of said weaving machines for generating an emergency signal of a priority level intermediate the levels of said high and low priorities, and means for counting the number of occurrences of said intermediate priority level signal within a predetermined period of time to activate the brake actuator of the associated weaving machine when said counted number reaches a predetermined value. 
     
     
       7. A method for controlling the sequence of stopping operations of a plurality of weaving machines during emergency conditions to minimize the loss of time due to the stoppage, comprising: providing first and second detectors associated with each one said weaving machines to generate a high and low priority emergency signals respectively when the associated weaving machine is under high or low priority emergency condition;   detecting whether there is any high priority emergency signal other than the high priority signal generated from said first detector;   activating a brake actuator of the associated weaving machine in response to said high priority emergency signal;   activating said brake actuator in response to said low priority emergency signal when there is no other high priority signal detected;   introducing a delay time in response to said low priority emergency signal when there is any other high priority signal detected; and   activating said brake actuator after the elapse of said delay time.